Irrlicht.Net is no longer developed or supported, Irrlicht.Net Cross Platform is a much more complete wrapper. Please ask your C# related questions on their forums first.
im currently working on a .Net Network engine for multiplayer games. Now i will ask if someone has ideas for features which should be implemented.
By now you can start a client or a server. Both can send an receive string, doubles and byte[], also ping other computers. Server can handle x clients (amount of clients can be set on start).